1. Field of the Invention
The invention relates to a method for fixing a flexible printed circuit (FPC) of a display. More particularly, the invention relates to a method for fixing a FPC of a display through a housing.
2. Description of the Prior Art
Liquid crystal display modules are widely applied to information products such as personal desktop computers, notebook computers, personal digital assistants (PDA), mobile phones, etc. due to the characteristics of light weight, low power consumption, small size, and little radiation pollution. Liquid crystal display modules are even poised to replace the CRT monitor and the conventional TV.
In order to satisfy the market for lightweight and small electronic products, manufacturers should continuously develop various component placements within the limited space of products. Usually, a liquid crystal display panel is connected to an external device by a flexible printed circuit (FPC) in order to control the general appearance of the panel. Because the FPC is flexible, the FPC is usually folded back according to the placement of the display module in order to save more space.
Please refer to FIG. 1 and FIG. 2. FIG. 1 is a schematic front view of a prior art flat display module 10, and FIG. 2 is a schematic back view of the prior art flat display module 10 of FIG. 1. The prior art flat display module 10 comprises a housing 12, a flat display panel 14 positioned in the containing space of the housing 12, and an FPC 16 connected to the flat display panel 14. In addition, the backlight module comprises a reflector 18 positioned on the bottom thereof. The rectangular reflector 18 is seen in the housing 12 in the back view of the flat display module 10. As shown in FIG. 2, in order to save more space of the flat display module 10, the FPC 16 is folded back on the back of the flat display module 10. For the purpose of fixing the FPC 16, fixing glue is positioned between the reflector 18 and the FPC 16 so that the FPC 16 adheres to the back of the flat display module 10. A common adhered position of the fixing glue is shown as a dotted-line circle in FIG. 2. However, while the fixing glue adheres to the reflector 18, the FPC 16 pulls at the reflector 18 due to the strain of the FPC 16, and results in a mura on the flat display panel 14. On the other hand, because the folded-back FPC 16 pulls the fixing glue back, the reflector 18 becomes warped after a period, and the FPC 16 may not closely adhere to the back of the flat display module 10 any more. Thus, the display performance of the flat display panel 14 is influenced.
In order to solve the above-mentioned problem, one of the possible solutions is to reduce the size of the reflector 18 so that the fixing glue can adhere to the place around the reflector 18 to fix the FPC 16. Please refer to FIG. 3. FIG. 3 is a schematic back view of a prior art flat display module 10. As shown in FIG. 3, the lower part of the reflector 18 is narrower than the upper part of the reflector 18 so that the fixing glue 20 can adhere to the housing 12 or other rigid structure. Thus, the FPC 16 adheres to the back of the flat display module 10 without a warped reflector 18 or influence on the display images. However, changing the shape of the reflector 18 may cause some problems. One problem is light leakage from the back of the backlight module resulting from the narrower part of the reflector 18. Another problem is the difficulty of the adhering process due to the narrow space for the fixing glue 20. If the fixing glue 20 is carelessly applied to the surface of the reflector 18, the reflector 18 can still become warped. Still another problem is poor adhesion to fix the FPC 16 resulting from the narrow space for the fixing glue 20.
On the other hand, in some flat display module designs, fixing glue having electric conductivity is used as adhesive to fix the FPC. Such glue might be metallic glue, for example. Usually, the adhesion of this type of fixing glue is too poor to fix the FPC, and the poor adhesion causes some problems such as peeling.